Dry Eye Disease
Dry eye is a disease of the external surface of the eye that arises either due to decreased production of tears or an increased evaporation of tears and results in symptoms of ocular irritation. Dry eye affects males and females of all age groups. But anecdotal evidence suggests that dry eye disease is more prevalent in females. Sjögren’s syndrome, an auto-immune disease that causes the most severe form of dry eye, almost exclusively occurs in females. Dry eye disease affects 7-10 million Americans. Two-thirds of cases are moderately dry eyes and one-third are severe.
Etiology of dry eye disease
The ocular surface damage observed in dry eye disease can have a variety of etiologies such as: inflammation, autoimmune disease, hormonal imbalance, refractive surgery, vitamin A deficiency, blepharitis, scarring diseases of the ocular surface, chemical burns, radiation therapy, etc.
Symptoms and Signs of Dry Eye Disease
Dry eye is characterized by ocular irritation symptoms such as irritation, sandiness, grittiness, foreign-body sensation, dryness, itching, fatigue. Clinically, a dry eye patient often demonstrates an unstable tear film (short tear break-uptime), a hyperosmolar tear film and ocular surface epithelial damage (as observed by vital dye staining).
Treatment of Dry Eye Disease
Dry eye treatment largely involves palliative therapy such as rewetting agents (artificial tears, a $200-300 million industry). Recently, Cyclosporin A 0.05 % (Restasis) has been approved for the treatment of severe dry eye. Other therapeutic options include the use of mild steroids, the insertion of devices such as punctual plugs and surgical options such as partial / complete tarsorraphy. Several other drugs for dry eye therapy are being investigated by various pharmaceutical companies.
Dry Eye Research in our Lab:
We are interested in the role of inflammation in the pathogenesis of dry eye. In particular we study patients with mild-moderate dry eye disease as this is the most common and not well understood. The results from our research to date indicate that it is debatable that mild-to-moderate dry eye patients have ocular surface inflammation. Our research also suggests that the cytokine interleukin-1b is able to modulate other inflammatory cytokine gene expression in cultured corneal and conjunctival epithelial cells and modulate experimental dry eye in mice but probably does not play a role in moderate human dry eye. Currently we are very interested in establishing
Recent publications related to dry eye:
Narayanan S,Manning J, Proske R, McDermott AM. (2006) The effect of hyperosmolality on b-defensin gene expression by human corneal epithelial cells. In Press Cornea
Narayanan S,Miller LW, McDermott AM. Conjunctival cytokine expression in symptomatic moderate dry eye subjects. Invest Ophthalmol Vis Sci. 2006,47, 2445-2450.
Narayanan S, Miller WL, Prager TC, JacksonJA, Leach NE, McDermott AM, Christensen MT, Bergmanson JPG. The diagnosis andcharacteristics of moderate dry eye in non-contact lens-wearers. Eye ContactLens 2005, 31, 96-104.
Narayanan S, Miller WL and McDermottAM. Expression of human b-defensins in conjunctival epithelium :relevance to dry eye disease. Invest. Ophthalmol. Vis. Sci. 2003, 44, 3795-3801.